Malaria is caused by Plasmodium falciparum (mainly in Africa) and Plasmodium vivax (mainly in Asia).
Pregnant women are more susceptible to malaria due to immunologic changes and placental sequestration of Plasmodium falciparum parasites.
Primigravidas have a higher prevalence of placental malaria, especially in areas with stable transmission, i.e. endemic regions.
Population and the effects on malaria in pregnancy
| Population | Malaria in pregnancy |
|---|---|
| Primigravida | Higher prevalence of placental malaria than multigravidas since the placenta is immunologically naive. Local immunity develops with subsequent pregnancies. |
| Stable (endemic) transmission areas | Pregnant women are semi-immune and have a low prevalence of peripheral parasitaemia but a high prevalence of placental malaria. Women are often asymptomatic due to low peripheral parasitaemia hence the need for intermittent-preventive treatment |
| Unstable tranmission areas | Pregnant women have low-acquired immunity and are more likely to be symptomatic, and develop severe malaria and anaemia |
| HIV-positive | HIV-positive women are more likely to have malaria parasitaemia than HIV-negative women. The efficiency of antimalarials may also be decreased. |
- Pathophysiology
- Immunosuppression
- Hormonal changes, e.g., increased progesterone and cortisol suppress maternal immune response. Primigravidas have a higher cortisol levels than multigravidas.
- Placental malaria
- The placenta is immunologically privileged making it easier for Plasmodium falciparum to evade clearance
- Plasmodium falciparum infected erythrocytes express variable surface antigens (VSAs) that bind to chondroitin sulfate A (CSA) on the syncytiotrophoblasts lining the intervillous space in the placenta
- Parasites are sequestrated in the intervillous space causing altered placental integrity → reduced nutrient and oxygen transport → low-birth weight and fetal growth restriction
- Severe anaemia also contributes towards low birth weight and fetal growth restriction
- Immunosuppression
- Signs and symptoms
- Fever and chills
- Headache
- Malaise
- Jaundice
- Seizures
- Respiratory distress
- Investigations
- Peripheral blood smear microscopy for parasitaemia
- Placental blood smear or biopsy postpartum to confirm placental malaria
- Rapid diagnostic tests (RDTs) to detect histidine-rich proteins (HRP-2) for Plasmodim falciparum
- Treatment
- Foetal monitoring
- Prevent hypoglycaemia particularly if taking quining
- Correct anaemia
- Antipyretics
- For uncomplicated malaria:
- Oral quinine during the first trimester
- Oral artemether-lumefantrine or quinine during the second and third trimester
- For severe malaria
- Intravenous quinine or artesunate
- Prevention
- Intermittent preventive treatment for malaria in pregnancy (IPTp) using 3 tablets of sulphadoxine-pyrimethamine (SP)
- Administer at each visit after quickening and ensure a minimum of 2 doses with an interval of at least 4 weeks
- Taken at quickening since fetal growth velocity is highest after this period
- Withold high-dose folic acid tablets when taking SP and resume 14 days after IPTp if needed
- HIV+ women on daily corimoxazole chemoprophylaxis do not need SP for IPTp
- Long-lasting insecticidal nets (LLINs)
- Intermittent preventive treatment for malaria in pregnancy (IPTp) using 3 tablets of sulphadoxine-pyrimethamine (SP)
- Complications
- Maternal
- Severe anaemia (2 – 15%)
- Cerebral malaria
- Hypoglycaemia
- Pulmonary oedema
- Acute renal failure
- Maternal death
- Hypertension
- Placental infection
- Puerperal sepsis
- Foetal
- Maternal